When the gas bolier central heating turns itself off I notice what seems like a vibrating noise from the pipes, only for a few seconds. Apart from this noise the c/h works as normal. I do not notice this noise when the boiler is heating the water only. Any ideas?
Maybe the boiler is kettling after the boiler has shut down and the pump has stopped circulating the water, this would be due to the heat exchanger containing enough energy to continue heating the water for a few seconds.
As long as the water is not brought to boiling point, there is no problem.